from .managers import PostManager

class Post(Postable)
	# ...
	objects = PostManager()


public = Post.objects.public_posts()
public_apology = Post.objects.public_posts().filter(
	message_startswith='Sorry')


q1 = User.objects.filter(username__in=['a', 'b', 'c'])
q2 = User.objects.filter(username__in=['c', 'd'])

# some operations can be done using the Q object
from django.db.models import Q
# Union
User.objects.filter(Q(username__in=['a', 'b','c']) | Q(username__in=['c', 'd']))

# intersection
User.objects.filter(Q(username__in=['a', 'b', 'c']) & Q(username__in=['c', 'd']))

# difference 
User.objects.filter(Q(username__in=['a', 'b', 'c']) & -Q(username__in=['c', 'd']))
